After that, delete your old blockchain files from that folder (everything in that folder), you’ll want to let it re-download the blockchain. This shouldn’t take that long at this point, maybe 60-90 min, depending on network speed.

Build instructions are down that page. (NOTE: If the package libboost1.55-all-dev isn’t available, a later version should work. lubboost-1.58 is working for sure.)

After building, if you had not installed a previous version, you’re now ready to go.

If you had the old 0003 GUI wallet: Close your new 0004 GUI. Then take the the files you backed up, (bipcoinwallet.wallet, bipcoinwallet.addressbook, bipcoinwallet.cfg), and allow them to overwrite those same files in the ~/.bipcoin folder. Then you’re ready to go.